Bottom line, I wouldn't put your self in danger or anyone else for that matter. Upgrade to a truck or SUV that can handle the weight. You say worst case, 1.9 miles and a bridge but you will venture further over time...Don't risk it!! ...Also think of pulling it in and out of the water at the boat ramps, you need some power/weight behind you. Have you tried it yet to see how handles?? And Is the jeep 4 wheel drive??

OP, I would go against most of the advice you are getting in this thread and just do it. No point in getting a new tow vehicle. It's 1.2 miles, slow slow miles. I'm assuming you will not need to merge onto any highways. Steady as it goes and leave plenty of room in front of you.

A few years back my SUV was in the shop and we only had my buddies Jeep Wrangler to launch the boat. We only had to drive a block and and then back it into a launch, which had a tight parking lot with a moderate slope. This was a 95 Prostar 205, which only weighed 3500 lbs with trailer. As soon as he turned the front wheels to angle in the boat, the rear end of the jeep squatted, pretty much lifting the front wheels off of the ground. The jeep and the boat then slid down the rest of the parking lot, directly into the launch. Only by pure luck did everything line up and we didn't hit the dock, or go off the side into all of the trees. As the trailer entered the water, the weight was lifted off of the back of the jeep and he was finally able to stop. We almost trashed my boat and my buddies Jeep. Obviously we learned a very valuable lesson that day, don't make the same mistake!